Fusible air control for unit heaters



Jan. 6, 1931. L. D. HARNETT 1,787,623

FUSIBLE AIR CONTROL FORUNIT HEATERS Filed Aug. 29, 1929 3 Sheets-Sheetl Ila.

A TTORNE V ENTOR m 9% Z JPW Jan 6, 1931. D. HARNETT FUSIBLE AIR CONTROL FOR UNIT HEATERS File'd Aug. 29, 1929 3 Sheets-Sheet 2 Vli/VTOR A TTORNE V 3 Sheets-Sheet. 3

L. D. HARNETT FUSIBLE AIR CONTROL FOR UNIT HEATERS Filed Aug. 29, 1929 11v VENTOR A TTORNE y Jan 16,1931.

Patented Jan. 6, 1931 UNITED STATES PATENT OFFICE LEWIS D. BARNETT, OF COLUMBUS, OHIO, ASSIGNOB TO THE BUCKEYE BLOWER. COI- PANY, O1 DAYTON, OHIO, A CORPORATION 01! OHIO FUSIBLE AIR CONTROL FOR UNIT HEATERS Application med August 29, 1929. Serial No. 389,184.

My invention relates to heating and ventilating apparatus and particularly to unit heaters and ventilators.

It is the object of my invention to provide a" unit heater and'vent la'tor in which the air inlet damper will automatically close under the air pressure control for the damper in the event of a fire outside of the building. At the present time, fire regulations are very strinent as to fire windows, but, with the present design of heating and ventilating unit, a large opening for inlet air is left in the wall beneath such windows com letely nullifying the fire regulations for sea ing one building from fire in another.

In unit heaters and ventilators in which the dampers are operated by a thermostat controlling'an air pressure line which operates a diaphragm or air motor, it is my object toplace a portion of this air line bypassing the thermostat and adapted to directing ad acent this opening,

control the air motor on the damper outside of the building adjacent the air inlet opening. In such portion outsidethe buildit is my object to provide a fusible member which, upon being melted, will open the line and willallow the air pressure to close the damper immediately irrespective of the damper conditions in the room in which the unit heater and ventilator is located.

Referring to the drawings:

Figure 1 is a vertical section through a wall of a building, the floor, and the unit heater and ventilator;

Figure 2 is a detail front elevation with the casing in section showing the arrangement of the air motor, damper and piping;

Figure 3 is a detail section of the lower part of Figure 1 enlarged.

Referring to the drawings in detail, 1 is a unit heater and ventilator casing havinga fresh air inlet opening 2 for receiving a1r through the opening 3 in the wall 4, such opening being provided with the usual storm louvers 5. The casing is provided with a recirculation air inlet openlng 6 at the bottom of the casing. The introduction of the air through the o nings2 and 6 is controlled by the main in et damper 7 which is pivoted at 8 on the floor of the casing. This damper is operated by the links 9, 10,11 and 12. The air motor 13 in which there is a piston and piston rod 14 is adapted to operate such links against the resistance of the spring 15.

The spring 16 connected to the arm 17 on the operating shaft 18 serves to hold the damper in either of its positions and to resist its movement from one position to the other. The air pressure line 19 is provided for supplying air through the thermostatic valve 20 and pipe 21 to the air motor 13.

When the damper lowers the thermostat 20 opens its valve and permits the air in the line 19 to close the damper 7 shutting off the fresh incoming air. a

When the damper rises the valve 20 closes and the spring 15 opens the damper to admit fresh air.

This air line 19 is provided with a by-pass loop 22 which conveys air around the thermostatic valve 20 for directly operating the air motor 13 to close the damper 7 to revent air from entering the opening 2. T is bypass 22 is only opened when heat outside of the building adjacent the air inlet opening 3 is sufiicientlygreat to fuse the fusible stop 23 which is located in the loop 22 and thus allow air to pass directly to the motor 13 and close the damper 7 and shut out any fire or gases from the outside of the building which would otherwise enter the building through the open damper 7 and the wall opening 3.

It will be understood that I desire to comprehend within my invention such modifications as may be necessary to adapt it to varying conditions and uses.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In combination, a unit heater and ventilator having an air inlet opening, a damper therefor, air operated means to close said damper,- and means adapted to be destroyed by heat for admitting said air to said air operating means to close the damper.

2. In combination, a unit heater and ventilator having an air inlet opening, a damper therefor, air operated means to close said damper, and means adapted to be destroyed by heat for admittin said air to said air operating means to c ose the dam r, said means in the air operatin means ing located outside of the buil mg in which the unit heater and ventilator is open adjacent the air inlet opening therefor.

3. In combination, a unit heater and ventilator having an air inlet opening, a buildmg wall having an air inlet opening therefor, air operating means, a damper for closing said opening operated thereby, means for conveyin a portion of said air operatin means outsi e of the building adjacent sai air inlet opening, and a heat fusible link in Bald means.

4. In combination in a unit heater and ventilator, a casing having an air inlet opening adjacent an air inlet opening in a wall, a damper for controllin said openings, air operated means for c osing said damper, heat operated means within the room in which said unit is located for controlling the closing of the damper, an air by-pass around said controlling means extending out of the room to a ploint adjacent said air inletopenings, and eat operated means therein for opening said by-pass to close said damper irrespective of any other means.

5. In combination, a unit heater and ventilator having an air inlet opening, a damper therefor, a wall having an air inlet opening associated therewith, air operated means for closin said damper, a thermostat in the room in which said unit is located for controlling the air operated means, a byas in theair operated means around said t ermostat extending to a point outside of the buildin wall adjacent the air inlet opening, and a usible link in said by-pass adjacent said opening.

6. In combination in a unit heater and ventilator of a casing having an air inlet opening at the bottom, an air exit opening at the top "and a re-circulation opening at the top, a damper alternately controlling said bottom' 0 enings, link mechanism for operating said amper, yielding means for maintaining said damper in either position, an air motor for. operating said link means in one direction, yielding means for operating thelink means in the other direction, an air pressure line for operating said motor, a thermostatically-operated valve therein, an air by-pass line around said thermostatic valve, a ortion of which extends outside of the buil ing adjacent the air inlet opening and a fusible link in said portion of said bypass.

In testimony ature.

whereof, I afiix mylsi TT LE WIS D. HA 

